Prof.dr. R.J.F. Cramer (Ronald) Faculty    Mathematics & Natural Sciences E-mail    cramer@math.leidenuniv.nl Phone    020 592 4166     Date of birth February 3, 1968 Place of birth Haarlem Study Mathematics Ph.D. January 31, 1997 Dissertation Modular design of secure yet practical cryptographic protocols Date of accession June 1, 2004 Subject Cryptology

Keywords

Fundamental and practice-oriented cryptology, algebraic and number theoretical aspects, reductionistic security, secure computation, secure communication

My inspiration

Cryptology deals with mathematical techniques for design and analysis of algorithms and protocols for digital security in the presence of malicious adversaries. For example, encryption and digital signatures are used to construct private and authentic communication channels, which are instrumental to secure Internet transactions. Another example of increasing importance is secure computation, which in principle enables an arbitrary computation to be distributed among the processors in a network so that computations remain secret and are performed correctly, even if a certain quorum of the network is under full control of an adversary. Advancing our understanding of secure communications and secure computation is among the primary goals in cryptology. It is fascinating and promising that the connection between cryptology and fields such as algebra, number theory, geometry, complexity theory, quantum physics and information theory is in the process of becoming still deeper than ever before.

Titles of major publications

• (2005) Ronald Cramer, Ivan Damgaard, Yuval Ishai, "Share Conversion, Pseudorandom Secret-Sharing and Applications to Secure Computation", Proceedings of Theory of the Second Theory of Cryptography Conference (TCC 2005), MIT, Cambridge, MA, USA, Springer Verlag LNCS, volume 3378, pp. 342--362, February.
• (2003) Ronald Cramer, Victor Shoup, "Design and Analysis of Practical Public-Key Crypto-Systems Secure against Adaptive Chosen Ciphertext Attack", SIAM Journal on Computing, volume 33 (1), pp. 167-226.
• (2002) Ronald Cramer, Serge Fehr, "Optimal Black-Box Secret Sharing over Arbitrary Abelian Groups", Proceedings of the 22nd Annual IACR CRYPTO, Springer Verlag LNCS, volume 2442, pp. 272--287, August.
• (2002) Ronald Cramer, Victor Shoup, "Universal Hash Proofs and a Paradigm for Adaptive Chosen Cipher-Text Secure Public-Key Encryption", Proceedings of the 21st Annual IACR of EUROCRYPT, Springer Verlag LNCS, volume 2332, pp. 45--64, April 2002.
• (2000) Ronald Cramer, Ivan Damgaard, Stefan Dziembowski, "On the Complexity of Verifiable Secret Sharing and Multi-Party Computation", Proceedings of the 32nd Annual ACM Symposium on Theory of Computing (STOC '00), ACM Press, pp. 325--334, May.

Links

http://www.math.leidenuniv.nl/~cramer

http://www.cwi.nl/~cramer